625 research outputs found
The merits of Universal Language Model Fine-tuning for Small Datasets -- a case with Dutch book reviews
We evaluated the effectiveness of using language models, that were
pre-trained in one domain, as the basis for a classification model in another
domain: Dutch book reviews. Pre-trained language models have opened up new
possibilities for classification tasks with limited labelled data, because
representation can be learned in an unsupervised fashion. In our experiments we
have studied the effects of training set size (100-1600 items) on the
prediction accuracy of a ULMFiT classifier, based on a language models that we
pre-trained on the Dutch Wikipedia. We also compared ULMFiT to Support Vector
Machines, which is traditionally considered suitable for small collections. We
found that ULMFiT outperforms SVM for all training set sizes and that
satisfactory results (~90%) can be achieved using training sets that can be
manually annotated within a few hours. We deliver both our new benchmark
collection of Dutch book reviews for sentiment classification as well as the
pre-trained Dutch language model to the community.Comment: 5 pages, 2 figure
An evolutionary algorithm for finding diverse sets of molecules with user-defined properties
Abstract The multidisciplinary field of drug discovery deals with the discovery and synthesis of novel medications. For over half a century, Computer Science has aided chemists in exploring the extremely large chemistry space that comprises the set of all drug-like molecules. But only in recent years have the technological advances in computational power and the development of novel algorithms enabled researchers to start experimenting with in silico screening of promising compounds. While many classes of algorithms have been successfully applied in this field, one of the most prevalent is the class of Evolutionary Algorithms (EA). This nature inspired optimization algorithm, which will be discussed in this thesis, allows for the exploration of large search spaces with the goal of finding good solutions to a given problem. Although the classical EA uses the notion of diversity to find solutions, they do not necessarily have the goal of finding a diverse set of solutions. This thesis discusses the application of the novel Evolutionary Level-Set Algorithm (ELSA) for finding not only a good set of solutions, but also for finding a diverse set of molecules given certain constraints on these molecules. This diverse set can be explored by the chemist to enhance creativity and provide a starting point for further research. For the comparison of molecules and to measure similarity, a proper metric is needed, which the algorithm uses to measure the diversity of the population. The ELSA algorithm, along with five different diversity indicators were implemented as an extension module in METool (Molecular Evolutionary Tool). Also, experiments were conducted to test the performance of ELSA and the various diversity indicators in the context of finding diverse sets of molecules with user-defined constraints. The results of the experiments show that the simple measures, despite being of low computational complexity, perform surprisingly well when used as a quality indicator in the ELSA algorithm
Coastal management and long-term foredune behavior:characterizing semi-natural foredune evolution
Techniques for solving bound state problems
We have used different methods to obtain the bound states of a Hamiltonian of a relativistic two scalar particle system in a local potential. The potentials we are interested in are binding and confining potentials, that are associated with particle exchange. The issues we concentrate on when comparing the different methods are ease of numerical implementation, accuracy and stability. To check our codes we have made use of several potentials for which the bound states are known in the nonrelativistic situation. Finally we calculate the bound states for the Yukawa potential in the relativistic situation and look at the collapse of the wave functions in this situation
CONIFEROUS WOODS IN THE EARLY PLEISTOCENE BROWN COALS OF THE LEFFE BASIN (LOMBARDY, ITALY). Ecological and biostratigraphic inferences
49 autochthonous wood samples collected in brown coal from the Leffe palustrine deposits (Early Pleistocene, Lombardy, N-Italy) have been identified and their stratigraphical position has been discussed in comparison with pollen spectra. A peat level in the lower part of the succession contains Piceoxylon wood. Pollen spectra point to a conifer forest of dry and cool climate. Glyptostroboxylon tenerum, Chamaecyparis, Pinus aff. tabulaeformis, Carya, Pterocarya, Alnus, Fraxinus and Celtis woods have been identified from the "Main" brown coal layer in the middle (biogenic) unit of the Leffe Formation. The coniferous woods are described and some inferences about their ecological requirements are presented. These trees formed part of the swamp vegetation during interglacial phases. Pinus occurred, only during meso/oligotrophic phases. The biostratigraphic interest of these finds and climate dynamics are discussed, in order to interpret the discontinuous record of the "Tertiary plants" in Northern Italy during lowermost Pleistocene
Decadal-scale morphologic variability of foredunes subject to human interventions
Foredunes, the first row of dunes when viewed from the beach, fulfill an important task when it comes to protecting the hinterland against flooding from the sea. Due to climate related factors such as rising sea levels and an increase in extreme storm conditions, this task is under increasing pressure.\ud
As dunes are not static landscape features, but their form and position change through time, the level of safety they provide also changes through time. It is important to note that dunes that are essential in protecting the hinterland against flooding are mostly managed by man to secure a minimal level of safety. The present Coastal Policy (3e Kustnota, Ministerie van V&W (2000)) states that dunes should not only offer protection today, but also continue to do so in the coming 50 to 200 years.\ud
It appears that at a time period of decades to centuries, there is hardly any understanding on the form and position of coastal dunes that are subject to interventions. Therefore, the first objective of this study was to analyze the changes in shape of these dunes over a time period of approximately 50 years. For this time period, data is available from the so-called Jarkusdatabase\ud
(yearly coastal measurements), that show the yearly cross-shore development of the dunes
The efficacy of different torque profiles for weight compensation of the hand
Orthotic wrist supports will be beneficial for people with muscular weakness to keep their hand in a neutral rest position and prevent potential wrist contractures. Compensating the weight of the hands is complex since the level of support depends on both wrist and forearm orientations. To explore simplified approaches, two different weight compensation strategies (constant and linear) were compared to the theoretical ideal sinusoidal profile and no compensation in eight healthy subjects using a mechanical wrist support system. All three compensation strategies showed a significant reduction of 47-53% surface electromyography activity in the anti-gravity m. extensor carpi radialis. However, for the higher palmar flexion region, a significant increase of 44-61% in the m. flexor carpi radialis was found for all compensation strategies. No significant differences were observed between the various compensation strategies. Two conclusions can be drawn: (1) a simplified torque profile (e.g., constant or linear) for weight compensation can be considered as equally effective as the theoretically ideal sinusoidal profile and (2) even the theoretically ideal profile provides no perfect support as other factors than weight, such as passive joint impedance, most likely influence the required compensation torque for the wrist joint
1031-35 Value of Ibopamine as Adjunct to Maximal Oral Medication in Patients with Moderately Severe Congestive Heart Failure; a Double-Blind, Placebo-controlled Study
Multiple drug therapy, including ACE inhibitors, diuretics, vasodilators and digoxin is currently used to reduce signs and symptoms of chronic heart failure (CHF). Optimal treatment of these patients (pts) is a major clinical problem, as the prevalence of CHF increases. Ibopamine, a novel oral dopamine agonist with peripheral vasodilating and neurohumoral inhibiting effects, may have additive value in the treatment of pts with moderately severe CHF, already treated with ACE-inhibitors.To evaluate the additive value of ibopamine as adjunctive to maximal CHF treatment we studied 60 pts with NYHA class III-IV CHF, who were assigned to treatment with ibopamine (3 dd 100mg) or placebo in a double-blind, randomized fashion.We examined the effect of ibopamine on peak oxygen consumption (VO2), neurohumoral factors and cardiac arrhythmias during 48 hrs ECG monitoring. Neurohumoral parameters were determined at rest and during exercise and included serum norepinephrine, epinephrine, aldosterone and plasma renin activity. All assessments were made at baseline and after 12 weeks of study treatment.Baseline dataOf the 60 pts, 40 pts (67%) had ischemic heart disease andlor old myocardial infarction, and 20 (33%) non-ischemic heart disease (16 pts (27%) dilated myocardiopathy). Mean age was 63±10 years, left ventricular ejection fraction 0.23±0.08, peak VO2 15.0±2.4 ml/min/kg and 44 of the patients (73%) were male. Background CHF therapy included ACE-inhibitors (100%), diuretics (100%), and digoxin, nitrates, amiodarone when required. At baseline resting serum norepinephrine was 724±78pg/ml, epinephrine 68±17pg/ml, aldosterone 0.50±0.08nmol/l and plasma renin activity 5.7±0.9ng/ml/hr.ResultsThe study was recently completed, the study data are currently analyzed and the results will be presented at the meeting
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